1. Field of the Invention
The present invention relates to a pulley cover assembly for a motorcycle transmission, and more particularly, to a pulley cover assembly for a motorcycle transmission which can permit not only secure support of a pulley rotatably mounted on an intermediate shaft of the motorcycle transmission to thereby ensure smooth rotating motion of the pulley with an improved rotational performance, but also hydraulic operation of a clutch operating mechanism to thereby ensure convenient clutch operation.
2. Description of the Related Art
In general, motorcycles perform transmission of rotatory power produced from a motorcycle engine via a motorcycle transmission. Then, the rotatory power is delivered to a driving pulley 1, which is connected to a driven pulley 2, mounted on a motorcycle's rear wheel, via a belt 3 as shown in FIG. 1, to thereby permit rotation of the rear wheel. The driving pulley 1 is located at one side of the motorcycle transmission so as to freely rotate on an intermediate shaft 4 of the motorcycle transmission. Such a driving pulley 1 is conventionally interposed between the motorcycle's front and rear wheels.
A pulley cover assembly 5 is fixedly mounted at one side of the motorcycle transmission, and as shown in FIG. 1, serves to cover and protect the driving pulley 1 while improving the appearance thereof. The pulley cover assembly 5 includes a clutch operating mechanism to permit engagement or disengagement of a clutch disc included in the motorcycle transmission.
Referring to FIG. 2 illustrating the interior configuration of the conventional pulley cover assembly 5, the pulley cover assembly 5 consists of a pulley cover 5a to cover and protect the driving pulley 1, and the clutch operating mechanism mounted at one side of the pulley cover 5a. 
The driving pulley 1 is engaged at a rotational center portion thereof with teeth of an output gear 6 of the motorcycle transmission so as to rotate simultaneously with the output gear 6. A separation-preventing plate 15 is coupled to both the engaged driving pulley 1 and the output gear 6 to prevent unintentional separation of the driving pulley 1 from the output gear 6. The output gear 6 is supported on the outer circumference of the intermediate shaft 4 via bearings 7 in a rotatable manner. Consequently, the driving pulley 1 is supported on the intermediate shaft 4 so as to freely rotate about the intermediate shaft 4.
The pulley cover Sa defines an interior space suitable to accommodate the driving pulley 1 and is opened at one side thereof to permit access to the driving pulley 1. The pulley cover 5a, covering the driving pulley 1, is fastened to a transmission cover 8 by means of fasteners.
The clutch operating mechanism includes a case 9 attached to the outer side of the pulley cover 5a, and a fixed plate 10 and a moving plate 11 disposed inside the case 9. The fixed plate 10 is affixed to an inner surface of the case 9 by fixing means, while the moving plate 11, positioned to face the fixed plate 10, is supported by the case 9 so as to freely rotate about the same axis as the intermediate shaft 4.
To the moving plate 11 is fastened one end of a clutch rod 12. The other end of the clutch rod 12 is inserted through an axial through-bore centrally formed in the intermediate shaft 4 by passing through the pulley cover 5 and comes into contact with a connection rod 13, which is connected to a clutch disc (not shown) of the motorcycle transmission.
Meanwhile, a ball 14 is interposed between the fixed plate 10 and the moving plate 11. The ball 14 is seated in an inclined circumferential groove lib defined at a surface of the moving plate 11. A distal end 11a of the moving plate 11 opposite to the inclined circumferential groove 11b is connected to a clutch lever (not shown), provided at a motorcycle handle, via a wire (not shown).
With such a configuration, when a motorcyclist pulls the clutch lever, the wire, connected between the clutch lever and the moving plate 11, is pulled to rotate the moving plate 11. The rotation of the moving plate 11 causes the ball 14 to move toward a shallow side of the inclined circumferential groove 11b to permit the moving plate 11 to move far away from the fixed plate 10 toward a position as is shown in FIG. 2. Thereby, by movement of the rotating moving plate 11, the clutch rod 12 and the connection rod 13 cooperate to drive the clutch disc (not shown) of the motorcycle transmission to implement clutch operation. Conversely, if the motorcyclist releases the clutch lever, the connection rod 13, the clutch rod 12 and the moving plate 11 are successively returned to their original positions upon operation of an elastic restoration means provided at the clutch disc.
However, with the conventional pulley cover assembly 5 configured as stated above, since one side of the driving pulley 1 is in an unsupported unstable state although the other side of the driving pulley 1, which is rotatably mounted on a distal end of the intermediate shaft 4 protruding from the motorcycle transmission, is supported by the transmission cover 8, there is a problem of an shivering phenomenon on the distal end of the intermediate shaft 4 and on the pulley 1 when a driving load of the motorcycle is applied to the pulley 1. Such an shivering phenomenon induces undue noise, deteriorates rotational performance of the pulley 1, and results in wear or degradation of elements associated with a specific portion of the pulley 1 rotatably supported on the intermediate shaft 4, reducing the life span of the pulley 1.
Further, the clutch operating mechanism of the conventional pulley cover assembly 5 is inconvenient in use because it must be only manually driven through linear movement of the moving plate 11 caused by a pulling force of the wire.